By William Mauldin and Courtney McBride

WASHINGTON -- Secretary of State Mike Pompeo said the U.S. is planning measures to address human-rights violations in China's Xinjiang region, furthering the Trump administration's recent confrontation with Beijing.

"I don't want to get in front of the final decision, but you can rest assured there are further actions," Mr. Pompeo told a Senate panel Thursday when asked about the U.S. response to China's mass detentions of Uighurs and other mainly Muslim ethnic groups in the northwest Xinjiang region.

At the hearing before the Senate Foreign Relations Committee on the State Department's budget and policies, Mr. Pompeo faced varied questions on the movement of U.S. troops from Germany, the Ukraine investigation and, as he acknowledged, the insufficient diversity among the nation's diplomatic corps.

Mr. Pompeo also defended the administration's $41 billion budget request for the State Department and the U.S. Agency for International Development for the coming fiscal year as sufficient.

Lawmakers previously have described the requested budget as "dead on arrival" for its cuts to key programs. Mr. Pompeo said the expenditures would help fight authoritarianism, protect Americans during the coronavirus pandemic and safeguard "unalienable rights."

The appearance by Mr. Pompeo follows months of wrangling between the department and Congress over nominations, access to information, his recommendation that President Trump fire an inspector general and the willingness of senior officials to appear before relevant committees.

Oh China, Mr. Pompeo drew praise from lawmakers for his tough approach toward Beijing, including in a speech last week that criticized Chinese leader Xi Jinping by name.

Sen. Mitt Romney (R., Utah), a frequent critic of the president, called the approach a "welcome departure from the president's fawning praise of Xi Jinping and celebration of agreements that China hasn't honored."

While the administration has pursued an increasingly tough-minded China policy, President Trump has mixed harsh criticisms of Beijing over its handling of the coronavirus outbreak with positive comments about Mr. Xi. In January, after bruising negotiations, the two sides signed a trade agreement that requires heavy Chinese purchases of U.S. exports that appear unlikely to materialize this year.

Asked about the recent closure of China's consulate in Houston, Mr. Pompeo said the outpost was a "den of spies" and that Chinese operatives "not only have the capability but also the intention of conducting disinformation campaigns in the United States."

Some of Mr. Pompeo's most forceful comments were about China's treatment of Muslim minorities in Xinjiang. He called the mass detentions in Xinjiang the "worst human rights violation we have seen this century."

Earlier this month, the Treasury and State departments imposed sanctions on Chinese officials involved in the suppression, including Chen Quanguo, the Chinese Communist Party secretary for Xinjiang and a member of the ruling Politburo.

A spokesman for the Chinese embassy in Washington didn't immediately respond to a request for comment on possible new sanctions or other measures aimed at Xinjiang. Officials in Beijing say its operations in Xinjiang, including the detention of what academic researchers believe is more than a million Muslim citizens, are China's domestic affairs and needed to curb dangerous Muslim extremism.

Mr. Pompeo told the senators that business pressure may be key to getting Beijing to change its behavior in Xinjiang. He reiterated a notice the State Department and three other agencies issued last month warning businesses that they risk possible sanctions violations or reputational damage if they retain suppliers or customers in Xinjiang.

Several senators spoke in support of closer ties with Taiwan, the democratic, self-ruled island Beijing claims as China's. Mr. Pompeo said Washington is approving weapons sales to Taipei. On whether the U.S. would pursue a free-trade agreement with Taiwan, he deferred to U.S. trade representative Robert Lighthizer and sidestepped comment on possibly upgrading diplomatic ties with Taiwan.

Write to William Mauldin at william.mauldin@wsj.com and Courtney McBride at courtney.mcbride@wsj.com